: Help please! Those knowledgeable of stand by generators, come on in!



CharlieB
10-31-12, 11:34 AM
Hello all!

We survived Sandy and much like the majority of the north east area we are and will be without power. In lieu of this we have decided to buy a generator but decided against a simple portable one.

What I ask are for any people here who have experience with what is important in buying a generator to give a little education so I can understand which is best for my needs. Here's some info about me :

- Approx 1800 sq. foot home
- Natural gas is an option for us
- Looking to power 2/3 TVs, Hot water heater, fridge, 5 lamps, 2 computers

I have tried to do some basic research and I am confused about the following :
- KW (some say 11 others 20...?)
- Starting watts and regular watts (I understand the difference but is starting watts and regular watts measured by the watts the unit produces?)
- Approx installation cost guess
- "200 amp "? (or something like that)

If you have any other info you would like to share that would be great! I am targeting an 11,000 watt unit...I don't have much to spend. I am not looking for a portable generator.

Submariner409
10-31-12, 11:55 AM
Use a Generac permanent model of about 13 - 15 kW surge, 12 kW steady, natural gas fueled. You will NEED a good auto transfer switch at the main panel. Install the unit away from large trees and either near a seldom occupied area of the home or at a far corner of the garage: You CAN hear these things run.

A hot water heater takes a stupendous amount of 220 volt power. Consider heating water on the (natural gas ??) cooktop or on a camp stove. An electric range also consumes quite a bit of 220.

To do it right will not be cheap. Ask yourself: How often do I really lose power, and for how long ??

Enough generator, gas piping, switches, cabling - labor - $8,000 +. (and now is NOT the time to start - absolute premium pricing and long wait times)

creeker
10-31-12, 02:24 PM
I have a 2300 watt generator in case of power failure, I can run my 1/4 h.p. forced air gas heater (i have a 1600 sq.ft. house) my t.v. and computer and some lights,
I dont even think of running my stove,fridge, water heater, I wired it so I can back feed the house through my dryer inlet (wall plug), I run a line directly from the gen. to the dryer female plug. I got the gen. for a good price, so I chanced that it would at least supply me with running my gas furnace. This is a small unit and I'm
surprised it can handle what it does.

Ranger
10-31-12, 03:36 PM
A 3500 watt generator runs everything in my house when needed (gas forced air heat) except the well pump and I can run that if I wire it directly. I have an auxiliary circuit wired into the breaker box running to a plug on a 6' cable in the garage. I just roll it out, plug it in, turn off the main and throw a switch by the breaker box to switch from utility service to generator.

EcSTSatic
10-31-12, 03:51 PM
Likewise. I have a 7500W generator that I can plug in and flip a transfer switch. I also installed a whole house surge protector panel.

You need to determine how much of a load you need to handle to correctly size your choice. Anything with a compressor is going to have a large startup rqmt. Then you need enough to sustain a constant load.

CharlieB
10-31-12, 07:47 PM
Im watching this guys but through my cell phone...have no power amd camt adequately respomd. THANK YOU for the replies. any more insight is greatly appreciated...some of this stuff is foriegn to me, like transfer switvhes and amps amd what not...

2sa
10-31-12, 09:13 PM
Im watching this guys but through my cell phone...have no power amd camt adequately respomd. THANK YOU for the replies. any more insight is greatly appreciated...some of this stuff is foriegn to me, like transfer switvhes and amps amd what not...

I am assuming you are reading via smartphone. Download an app called Grainger and search for standby generators. Local stores in every state.

creeker
10-31-12, 09:49 PM
The method I use is very simple, when the power goes off,

-I turn off main breaker to my house ( I tape it over to remind to not put it back on when hydro is back on).
- I then turn on my generator and run power line to my dryer female outlet, this is 220 volts. ( the dryer fixture splits it into 2 110 lines) this line is already installed.
- when hydro comes back on (can tell by neighbors lights) I then turn my gen. set off and turn my main breaker back on.

rodnok01
10-31-12, 11:21 PM
The method I use is very simple, when the power goes off,

-I turn off main breaker to my house ( I tape it over to remind to not put it back on when hydro is back on).
- I then turn on my generator and run power line to my dryer female outlet, this is 220 volts. ( the dryer fixture splits it into 2 110 lines) this line is already installed.
- when hydro comes back on (can tell by neighbors lights) I then turn my gen. set off and turn my main breaker back on.

You really shouldn't do that...
A transfer switch cuts all three legs of the power, doing what you are doing only cuts the two hots. Where workers can get hurt is when there is feedback from your generator on the neutral leg. So in reality you are energizing one leg from your generator. I have made this mistake myself until I had a lineman explain it to me.

As for OP, a Generac is a nice option but is alot of $$$ for an occasional use. 8K is a decent price for an install. If you don't have NG, the propane options suck gas like crazy, a couple 100lb tanks with a full load goes quicker than you think.
I have had portable generators for a long time and use them during power outages, I have heavy duty cords, surge protectors and a window ac unit just for hurricane season. I tune my generators up once a year, fire them up 2-3 times a year and keep plenty of gas cans around. We have been without power for over a week before and were comfortable although not "comfy" using a portable. For around 1K you can set yourself up with a nice generator and all the goodies you need, even stepping up to a couple hondas(can you say quiet) for not too much more.

Ranger
11-01-12, 11:52 AM
You really shouldn't do that...
A transfer switch cuts all three legs of the power, doing what you are doing only cuts the two hots. Where workers can get hurt is when there is feedback from your generator on the neutral leg. So in reality you are energizing one leg from your generator. I have made this mistake myself until I had a lineman explain it to me.

I'm confused. :hmm: How can you feedback if the mains are off?

dkozloski
11-01-12, 12:45 PM
Portable diesel generators are more reliable, reduced fire hazard because they don't need gasoline but will run on diesel fuel, heating oil, jet fuel, kerosene, or just about any petroleum that will flow through the pipe and have a much reduced carbon monoxide output. Every year people kill themselves with gas powered generators in the house, or in their garage from CO poisoning. Visit the construction equipment auctions and look for the portable lighting setups on a trailer that contractors use that include a generator and a folding mast with a couple of big lights on it. These things will run for years as long as you keep oil in the engine and fuel in the tank.

EcSTSatic
11-01-12, 12:52 PM
I'm confused. :hmm: How can you feedback if the mains are off?

Don't the main breakers just control the hot (black) lead? If you plug in to an outlet wouldn't you be feeding the white (return) lead?

Edit: maybe that's wrong. Really, that's all a transfer switch does too; switch the the source to the hot lead. The white neutral wire and ground are all in common.

dkozloski
11-01-12, 01:51 PM
Don't the main breakers just control the hot (black) lead? If you plug in to an outlet wouldn't you be feeding the white (return) lead?

Edit: maybe that's wrong. Really, that's all a transfer switch does too; switch the the source to the hot lead. The white neutral wire and ground are all in common.The white neutral, the safety ground wire, the neutral wire off the pole, and earth ground are all tied together in the service entrance. The transfer switch controls the hot lines only. This is assuming a normal 110/220V single-phase service.

rodnok01
11-01-12, 08:54 PM
A transfer switch cuts all three from the utility, NOT just the hot leads. That is the problem with only cutting the mains off, it only cuts the hot leads not the ground/neutral thus allowing you to backfeed the utility lines with power. The ground/neutral are continuous throughout the main panels on purpose to protect us.

http://www.reliancecontrols.com/Support.aspx?whatWhy

http://www.electrical-online.com/simple-diagram-of-a-generator-transfer-switch/

dkozloski
11-01-12, 09:01 PM
A transfer switch cuts all three from the utility, NOT just the hot leads. That is the problem with only cutting the mains off, it only cuts the hot leads not the ground/neutral thus allowing you to backfeed the utility lines with power. The ground/neutral are continuous throughout the main panels on purpose to protect us.

http://www.reliancecontrols.com/Support.aspx?whatWhy

http://www.electrical-online.com/simple-diagram-of-a-generator-transfer-switch/ Neutral, safety ground, and line feed neutral are all connected to a ground rod pounded into the ground. There is no way in hell to backfeed the powerline through the neutral/safety if you have operated the service disconnect. That's what it's for. The transfer switch should connect the generator neutral to the service neutral/safety as well as disconnect the loads from the line and connect them to the generator lines. The National Electrical Code does not permit any switching between the service neutral/safety, earth ground, and powerline neutral.

Ranger
11-01-12, 09:46 PM
That's kind of what I thought. I just turn the mains off.

The Raven
11-01-12, 09:57 PM
Neutral, safety ground, and line feed neutral are all connected to a ground rod pounded into the ground. There is no way in hell to backfeed the powerline through the neutral/safety if you have operated the service disconnect. That's what it's for. The transfer switch should connect the generator neutral to the service neutral/safety as well as disconnect the loads from the line and connect them to the generator lines. The National Electrical Code does not permit any switching between the service neutral/safety, earth ground, and powerline neutral.

All of this is assuming the electrical system is properly grounded. A utility worker cannot assume. He doesn't know who may have worked on the electrical system in your house and if the resulting work was inspected and approved. Unless you are a properly trained and licensed electrician/electrical engineer, you don't know either. If the service is dead, and your electrical system is not adequately grounded, a generator most certainly can backfeed into the service neutral. This is of particular concern if you are using a cheap generator, which at a time like this, is pretty common.

rodnok01
11-01-12, 10:28 PM
dkozloski, No disagreement up to and including the main service panel. The ground/neutral has to be one contiguous connection. The transfer switch is designed to completely seperate two different power sources. The problem is as The Raven has mentioned that the neutral is the issue as it can backfeed the utility lines. The other issue is a short on the utility side can feed through the lines and zap your stuff if the neutral is connected and you have power on your end.
Not trying to start or continue an argument but I didn't make this stuff up, try a google search. Was trying to inform the OP of an unsafe( and prohibited by code) practice.

EcSTSatic
11-02-12, 09:18 AM
Here's a link to wiring a transfer switch. It doesn't look like there's a way to backfeed

http://www.renovation-headquarters.com/generator-transfer-switch.htm

dkozloski
11-02-12, 11:42 AM
Here's a link to wiring a transfer switch. It doesn't look like there's a way to backfeed

http://www.renovation-headquarters.com/generator-transfer-switch.htm This is correct. You are switching downstream of the service disconnect and safety ground is not being switched. Switching of neutral/safety ground ahead of the main panel is not permitted.